Breathing Machine

Extensions

Encourage students to suggest variations of the investigation they conducted with their “breathing machines.” For example, students might want make their lung models “cough” or “sneeze.” For a more dramatic effect, place ½ teaspoon of baking soda or baby powder inside the balloon “lung” before making the lung model cough or sneeze.

Mention to students that a cough can reach speeds of 340 miles per hour. That’s faster than a propeller air plane (which moves at about 135 miles per hour!).

Remind students that when we breathe in, oxygen is removed from the air in our lungs and carbon dioxide is released. Ask, What happens to the other molecules and particles in air when we breathe in? Do we breathe nitrogen and other gases in and out? Do we also breath in harmful things in air?

Try making a more accurate model by filling the inside of the lung model with water.